PITTSBURGH — Think of them as the $10 million questions: Why do so many older people have so much trouble sleeping, and is there any help for them that doesn't involve drugs?

The University of Pittsburgh has received a $9.8 million grant from the National Institute on Aging to look for answers. The five-year study, to be called AgeWise, will recruit some 400 seniors to help solve the riddle.

About 25 percent of people over 60 have trouble getting to sleep or staying asleep. If the insomnia is severe enough, it can impair function and increase the risk of other medical problems.

It also can lead people to overmedicate themselves with prescription or over-the-counter drugs.

The goal of the study is to better understand the biological causes of insomnia and then find the most effective non-pharmaceutical solutions for each cause, said Dr. Timothy H. Monk, director of the Human Chronobiology Research Program at the Western Psychiatric Institute & Clinic and the study's lead investigator.

"The strength of this research project is that we simultaneously can attack the problem on several different fronts," Monk said.

"Insomnia in seniors can result from biological clock problems, sleep intensity problems, stress and arousal issues, the functional anatomy of the patient's brain, and particular issues of genetic makeup. All of these different research issues will be covered in our AgeWise study."

Sleep disorder breathing is excluded from the study, he said.

As for why these issues arise in older people who were not bothered by them before, Monk said, "There are a lot of things we don't do as well at 60 as we did at 20. I can't play tennis now as well as I did 40 years ago. One has to recognize sleep as one of those things, but there are tricks, attitudes and practices that can help."

Within each category of sleep problems, Monk said, researchers will look at how older adults with insomnia differ from those without it.

They also will study whether the success or failure of therapy is related to these categories.